The correct option is B Orientation
Magnetic quantum number is one of the quantum numbers represented by ml.
The values of this number describes the orientation of the orbital in space relative to the other orbitals in the atom.
For a certain value of l there are (2l + 1) integer values of ml.
When l=0, 2l +1 = 1 and there is only one value of ml, thus we have only one orbital i.e., s.
When l=1, 2l +1 = 3, that means ml has three values, -1, 0 and +1. Thus, p orbitals have three different orientations along x, y, z axes. These are labelled as px,py,and pz.